Can I Upgrade my Mini to OS X 10.6 Mountain Lion from 10.5.8?

I have a Mac Mini I bought in February of 2008. I have the OS X 10.5.8 which is the latest version for my computer according to the software update. I would like to upgrade to Mountain Lion 10.6 but am not sure if my mini is new enough. Does anyone know if it is? What's the easiest way to upgrade it? Thanks.